1. ACI, Guide to Shotcrete, Reported by ACI Committee 506, 1985.
2. Use of remote controlled spraying nozzle;Alberts,1973
3. Swedish shotcrete equipment and developments in fibrous shotcrete;Alberts,1976
4. Microwave Communications;Angelakos,1986
5. Development of shotcrete for metro construction in Washington;Bawa,1973